2. Insects of Medical Importance
Directly cause damage to human tissue
Act as Vectors for disease-causing
organisms
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Provide useful medical services/drugs
Are useful model systems in genetic
studies
3. Stinging Insects
Belong to the order Hymenoptera
Includes Paper wasps, Yellow Jackets, Honey
bees and Fire Ants
Have specialized venom glands attached to
“sting”
5. Envenomation Symptoms
Allergic reactions
Happen on the second (or later) sting
Antibodies to venom over-react and produce chemicals
(like histamines) that can damage neighboring cells.
Severe allergies can lead to anaphylactic shock, a
potentially deadly swelling of the airways and other
tissues.
If you’ve been allergic once, you’ve got a 60% chance of
being even more allergic next time. Carry an EpiPen!
8. Biting Insects
Saliva from several biting insects acts as an
allergen in many people
This can lead to intense itching when bites
are numerous:
10. Insects As Vectors
Several Biting Flies and Reduviid Bugs
carry infective stages of disease causing
pathogens. They are responsible for
spreading diseases like:
Malaria (Mosquitoes in genus Anopholes)
Plague (Rodent Fleas)
West Nile Virus (Mosquitoes)
Typhoid/Cholera/Dysentary (Muscid Flies)
11. Malaria
Caused by 4 species of protists in the genus
Plasmodium
Anopholes sp. Mosquitoes transmit the infective
stage of Plasmodium to people.
Active Plasmodium destroy large quantities of red
blood cells
There are 300-500 million infections/yr world-
wide, with 1 million deaths/yr.
Malaria has been virtually eradicated in the United
States (US citizens with malaria have contracted
it in other parts of the world)
13. Trypanasomiasis (Sleeping Sickness)
Caused by two subspecies of protists in the genus
Trypanosoma
Carried from host to host blood-sucking tsetse flies
Trypanosome infection is characterized by a series of
progressive symptoms:
Swelling at bite
Immune rxn (swelling of lymph nodes,etc)
Infection and swelling of CNS
Possible heart failure
These flies are found throughout middle Africa, where the
disease affects 66 million people in 36 countries
15. Chaga’s Disease
Caused by an American trypanosome,
Trypansoma cruzi
Spread by blood feeding kissing bugs
Occurs throughout Central and South America,
with some cases reported in the Southern US
Use “reservoir animals” like raccoons and
armadillos to keep population present
Heart and blood vessel damage is a common
symptom due to chemicals released by the
parasites in the blood
17. Pharmaceutically Important Insects
Venom is
extracted from
insects that
sting in order to
test people for
allergies and to
treat allergies
in a series of
small
injections.
18. Apitherapy
One of the major peptides
in bee venom, called
Melittin, is used to treat
inflammation in sufferers
of Rheumatoid Arthritis
and Multiple Sclerosis.
Melittin blocks the
expression of inflammatory
genes, thus reducing
swelling and pain.
It is administered by direct
insect sting, or
intramuscular injections.
19. Maggot Debridement Therapy
Recognized as useful by WWI surgeons
Used for
removing dead tissue from wound
Preventing infection
Speeding healing process
An extract, Allontoin, is used for treating the
infectious bone disease, Osteomyelitis
20. “Beetle Juice” Therapies
Cantharidin – the blister-
causing oil found in several
families of beetles (most
notably, Meloidae)
Historical use by Greeks and
Romans
Aphrodisiac????
Currently accepted by FDA in
2004 for treatment of warts and
other skin problems
22. What Can We Learn From a Fly?
How genes work
By using mutation studies and gene mapping:
Organization/Location
What genes code for which proteins
Development
Which cells become what body part, when and
HOW!
Proteins, enzymes, and neurotransmitters
involved.
23. Other Insect Models
Currently, We have sequenced the
following genomes:
Several species of Drosophila
Several species of disease-carrying mosquito
(Anopholes gambaei, Aedes, and Culex)
The Silkworm, Bombix mori
The Honey Bee, Apis mellifera
A Flour Beetle, Tribolium casteneus